The present invention relates to an oscillatory rotary actuator for the control of an adjustable valve, and more particularly to a system for controlling an adjustable valve, or series of such valves, from a central point or control panel located at a distance from the valve or series of valves.
For purposes of this invention, an adjustable valve is defined as one that can operate from a fully open to a fully closed position, and vice versa, by the arcuate movement or oscillation of the rotary piston(s) within the rotary actuator herein. The adjustable valve is preferably one that requires a rotation of less than 360.degree. to open and close the valve. Thus, the present invention will operate with a quarter turn valve, that is, one having a ninety degree turn from its open to close position, such as a ball valve or butterfly valve, or the like.
The present invention is generally applicable to remotely controlling an adjustable valve with a rotary actuator for regulating the flow of a fluid through a conduit in which the valve is interposed, although it is envisioned that the invention can be extended to the applications which require remote rotary actuation. The invention has particular application to the fire fighting industry, and more specifically for use on fire fighting vehicles that generally employ a complex system of pumps, valves and hoses for receiving and dispensing a fluid, commonly water, from and to various points located throughout the vehicle. The preferred valve used on fire trucks for controlling and dispensing water through the hose or conduit is a quarter turn ball valve.
The nature of a fire fighting vehicle is such that it generally contains a water discharge manifold located at a central pumping station for dispensing water through a series of lines that are controlled by multiple valves which are usually manually operated. Often times these valves, commonly ball valves, have to be operated in simultaneous fashion, requiring assigned manpower to monitor and control the various pressure and flow gauges to distribute the water as demanded by the multiple hoses or lines required to extinguish a fire. Thus, constant surveillance of the water pumping station, and each of the valves controlling the line pressures and water flow for the hoses employed, is necessary if the fire fighting apparatus is to operate in a safe and efficient manner. If there is a breakdown in any one of the lines, for example a ruptured hose, a quick and reliable shutdown of the respective line must be accomplished to ensure the safety of fire fighting personnel.
Moreover, when circumstances warrant, a rapid shutdown of a hose or line operating at or near full capacity must be accomplished in a manner that will avoid the severe back pressure that can cause a supply line or hose to rupture, or can damage a municipal water supply main if the line is connected thereto. Operators or attendants monitoring the pumping station of the fire truck often do not have advance warning to accommodate a sudden increase or decrease in line pressure either because of their remoteness from the control location or simply because of the timing involved in being able to adjust the pump pressure. The National Fire Protection Association (N.F.P.A.) has recently adopted standards requiring minimum operating times for the closing of valves on fire fighting apparatus.
In order to overcome the foregoing difficulties, a system is required whereby the pressures and/or flow rates of the individual valved lines emanating from the discharge pump of a fire fighting vehicle can be continuously and automatically monitored and controlled from a single location on the vehicle, or for that matter from multiple points or locations on the truck, so that individual line pressures and fluid flows can be remotely set and maintained to desired levels or positions as circumstances warrant.
Also required is an actuating apparatus for the control of each valve that is simple and compact in design, and which can be operatively connected to the valve in question without a significant demand for space on the fire fighting vehicle or a disassembly of the valve or line in question.
Many types of rotary actuators have been disclosed in the past, but they have been cumbersome, complex, and/or too costly to accommodate the control valves employed on a fire fighting vehicle. Actuators of this type are illustrated, for example, in Kinzie et al. U.S. Pat. No. 2,152,651 and in Sigmon U.S. Pat. No. 3,977,648.
Another drawback is that the inherent design of some rotary actuators is inefficient in terms of the power or hydraulic pressure needs to operate the actuator when torque demands for actuating the valve are high, usually when the fluid flowing through the valve is under a high amount of pressure. See, for example, Kalix U.S. Pat. No. 2,435,968; Shramo et al. U.S. Pat. No. 3,110,228; Reaves U.S. Pat. No. 3,688,645; to Reaves; and Smith U.S. Pat. No. 3,752,041.
A further obstacle is that other rotary actuators have been designed to be an inherent element of the valve for which they are meant to control, such as in Schnyder U.S. Pat. No. 1,646,631; Bischoff U.S. Pat. No. 2,168,255; Krumhansl U.S. Pat. No. 4,655,252; and in German Patent 2,011,639. These actuators work contrary to the "add-on" principle that is often mandated by the system utilized on a fire fighting vehicle. In other words, it is highly desirable for an actuator to simply be added to the existing valve hardware on a fire fighting vehicle, as opposed to having to disassemble or redesign the valve to incorporate or combine the actuator with the respective valve(s).
Automation or semi-automation of the valve system on a fire truck is also highly desirable for the safe and efficient operation of the truck and apparatus when it is being used to extinguish a fire. Various systems for the automatic control of a valve to regulate a continuous and/or intermittent flow of fluid through a conduit have been disclosed in the past, such as in Goike U.S. Pat. No. 3,225,785; Herrington et al. U.S. Pat. No. 4,069,292; Allen et al. U.S. Pat. No. 4,702,273; Gunda U.S. Pat. No. 4,798,527; Rothen U.S. Pat. No. 4,887,636; Olson, Jr. et al. U.S. Pat. No. 5,000,224 and pages 14-15 of "Fire Research News", Vol. 2, No. 1 (1988). The systems disclosed in the these publications, while utilizing pressure sensing means or flow sensing means, as may be the case, to invariably control the operation of a valve, are complex and therefore unreliable and/or inefficient to satisfy the operational and safety demands required of a system employed in fire equipment water control systems. They would additionally be inappropriate when used in conjunction with the rotary actuator according to the invention herein. Accordingly, there continues to be a need for an inexpensive, but highly effective and reliable apparatus and system for controlling an adjustable valve to regulate the flow of a fluid through a conduit or line, such as that utilized in fire equipment and fire fighting vehicles.
It is therefore an object of the present invention to provide an apparatus that will serve as an actuator for controlling the operation of an adjustable valve.
It is another object of the invention to provide an actuator that is relatively simple in design and operation.
It is yet another object of the invention to provide an actuator that can be retrofitted to an adjustable valve without a disassembly or change in design of the valve.
It is a further object of the invention to provide an actuator for the control of an adjustable valve so that the valve, or series of valves, can be operated from a single location at a distance from the valve(s) itself.
Another object of the invention is to provide a valve control system for remotely operating a valve, or series of valves, from a single location or control panel, to safely and reliably regulate the flow of a fluid through a conduit.
A further object is to provide a valve control system that will automatically regulate and monitor the flow of fluid through a conduit in response to a predetermined valve position setting; a predetermined fluid pressure setting; and/or a desired fluid flow rate setting.
And another object of the invention is to provide a valve control system that can be operated from any of a plurality of control panels strategically located to improve operational safety and efficiency, especially as it relates to systems on fire fighting vehicles.
These and other objects and features of the invention will become more readily understood from the following detailed description of the various meets and bounds of the invention in conjunction with the accompanying drawings.